Pod Autoscaler for tidb (SQL Processing) component in TiDB Cluster

Question

We are exploring the horizontal pod auto scaler (hpa) for the TiDB component. We tested it by deploying a small tidb cluster and auto-scaler hpa with basic configuration.

HPA was able to scale up and down the TiDB component. But if the replica count was not equal to the default value in TC spec the cluster state went into the not-ready status and tidb phase was changed to scale. This can cause maintenance hindrances for the operator.

Regarding the above-discussed cases, we have a few questions:

1. What was the outcome of HPA evaluation done by the PingCap team? (as said here it did not work: doc
2. Do you have such features in your roadmap?
3. If tc status is not-ready and tidb phase is scale, how exactly does it affect the TiDB cluster?
4. can we maintain a healthy state based on scale action done by hpa? or would it be anti-pattern for operator framework?

Start with the linked HPA/VPA FAQ and the reported behavior when the TC spec replica count differs from the HPA-managed count. Trace how that scaling affects TC readiness and the TiDB phase. Done means establishing answers to the four questions and identifying whether documentation or operator behavior needs to change.